Plz

think about it: since hard-shelled organisms evolved about 550 million years ago, billions of tons of limestone rock have been produced from their shells. limestone is made of calcium carbonate, with the formula caco3.

based on this, how do you think the amount of atmospheric co2 has changed in the last 550 million years, and how has this affected earth’s climate? explain your answer.

What evidence is there that convection occurs in earth’s troposphere?

Which of the following describes what an activator an enhancer are

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.